The “” has baffled scientists since the Cold War. NOAA thought the low-frequency quacking sound that occurs frequently off the coast of Antartica might have been the , an elusive Soviet submarine, or some mythical polar duck.
But now, researchers from Duke University have an answer: the . The smallest of the , this solitary creature stays close to dense sea ice.
“That makes them quite hard to study, too, and that’s also part of the reason why the signal has not been identified earlier,” . “It goes ‘quack, quack, quack, quack.’ It has this almost mechanical feel to it.”